U.S. Pat. No. 4,172,082 describes 3,5-bis(t-butyl)-4-hydroxybenzoyl-substituted thiophenes which exhibit antiinflammatory activity and are useful as starting materials in the process of the invention.
Enamines which are prepared by the process of the invention are disclosed in copending application Ser. No. 439,613. The processes claimed in that application involve an initial step in which the 3,5-bis(t-butyl)-4-hydroxybenzoyl-substituted thiophene is reacted with a strong base to provide a metal salt.